| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
i2c: imx: Cancel hrtimer before clearing slave pointer
In i2c_imx_unreg_slave(), the slave pointer is set to NULL after
disabling interrupts. However, a pending interrupt might already
have started the hrtimer (i2c_imx_slave_timeout) before the pointer
was cleared. If the hrtimer fires after i2c_imx->slave is set to
NULL, the timer callback i2c_imx_slave_finish_op() will call
i2c_imx_slave_event() with a NULL slave pointer, which results in a
use-after-free / NULL pointer dereference.
Fix by canceling the hrtimer and waiting for it to complete after
disabling interrupts, before clearing the slave pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Cancel delayed I/O APIC EOI handling before destroying vCPUs
Cancel (and flush) the I/O APIC's delayed EOI handling work during the
"pre VM destroy" phase, before vCPUs are destroyed, as processing the EOI
broadcast will inject another IRQ if the line is asserted, i.e. will try
to deliver an IRQ to the target vCPU(s). Canceling the work after vCPUs
are destroyed leads to UAF if the delayed work is processed after vCPUs are
destroyed.
BUG: KASAN: slab-use-after-free in __kvm_irq_delivery_to_apic_fast+0x9bf/0xa20 arch/x86/kvm/lapic.c:1250
Read of size 8 at addr ffff8880499abea0 by task kworker/1:2/1218
CPU: 1 UID: 0 PID: 1218 Comm: kworker/1:2 Not tainted 7.1.0-rc7 #5 PREEMPT(lazy)
Hardware name: QEMU Ubuntu 25.10 PC v2 (i440FX + PIIX, + 10.1 machine, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: events kvm_ioapic_eoi_inject_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378
print_report+0x139/0x4ad mm/kasan/report.c:482
kasan_report+0xe4/0x1d0 mm/kasan/report.c:595
__kvm_irq_delivery_to_apic_fast+0x9bf/0xa20 arch/x86/kvm/lapic.c:1250
__kvm_irq_delivery_to_apic+0xd8/0xbf0 arch/x86/kvm/lapic.c:1345
kvm_irq_delivery_to_apic arch/x86/kvm/lapic.h:129
ioapic_service+0x308/0x590 arch/x86/kvm/ioapic.c:492
kvm_ioapic_eoi_inject_work+0x13c/0x190 arch/x86/kvm/ioapic.c:532
process_one_work+0xa59/0x19a0 kernel/workqueue.c:3314
process_scheduled_works kernel/workqueue.c:3397
worker_thread+0x5eb/0xe50 kernel/workqueue.c:3478
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Note, the VM is unreachable once kvm_destroy_vm() starts, and scheduling
new work via kvm_ioapic_send_eoi() can only be done via KVM_RUN, i.e.
requires a live vCPU.
Alternatively, KVM could simply destroy the I/O APIC during the "pre" phase
of VM destruction, but that gets more than a bit sketchy as KVM expects the
I/O APIC to exist if ioapic_in_kernel() is true, and nested virtualization
in particular has a bad habit of touching VM-scope state during vCPU
destruction. E.g. attempting to free the PIC during the pre phase would
lead to a NULL pointer dereference in kvm_cpu_has_extint(), and it's not
hard to imagine the I/O APIC having a similar flaw. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: fix race of kfree vs kref_get_unless_zero
hci_conn::iso_data is accessed and modified without lock or RCU.
This leads to a race
[Task hdev->workqueue] [Task 2]
iso_recv iso_conn_put(conn)
conn = LOAD hcon->iso_data iso_conn_free(conn)
iso_conn_hold_unless_zero(conn) hcon->iso_data = NULL
kfree(conn)
kref_get_unless_zero(&conn->ref) /* UAF */
and also to races in iso_conn_add() vs. iso_conn_free().
Fix by adding spinlock hci_conn::proto_lock and using it to guard
hci_conn::iso_data. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv4: fib: Don't dump dying fib_info in fib_leaf_notify().
syzbot reported use-after-free in nsim_fib4_prepare_event(). [0]
The problem is that the following functions call fib_info_hold() /
refcount_inc() while dumping fib_info under RCU, which is unsafe.
* mlxsw_sp_router_fib4_event()
* rocker_router_fib_event()
* nsim_fib4_prepare_event()
refcount_inc_not_zero() must be used, but it would be too late
there.
Let's guarantee the lifetime of fib_info in fib_leaf_notify().
Note that IPv6 does not need the corresponding change since
fib6_table_dump() holds fib6_table.tb6_lock.
[0]:
refcount_t: addition on 0; use-after-free.
WARNING: lib/refcount.c:25 at refcount_warn_saturate+0x9f/0x110 lib/refcount.c:25, CPU#0: kworker/u8:15/3420
Modules linked in:
CPU: 0 UID: 0 PID: 3420 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: netns cleanup_net
RIP: 0010:refcount_warn_saturate+0x9f/0x110 lib/refcount.c:25
Code: eb 66 85 db 74 3e 83 fb 01 75 4c e8 1b f1 22 fd 48 8d 3d 84 cb f1 0a 67 48 0f b9 3a eb 4a e8 08 f1 22 fd 48 8d 3d 81 cb f1 0a <67> 48 0f b9 3a eb 37 e8 f5 f0 22 fd 48 8d 3d 7e cb f1 0a 67 48 0f
RSP: 0018:ffffc9000f2c7270 EFLAGS: 00010293
RAX: ffffffff84a18858 RBX: 0000000000000002 RCX: ffff888032ff9ec0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8f9353e0
RBP: 0000000000000000 R08: ffff888032ff9ec0 R09: 0000000000000005
R10: 0000000000000100 R11: 0000000000000004 R12: ffff8880570cc000
R13: dffffc0000000000 R14: ffff88802b40563c R15: ffff8880570cc000
FS: 0000000000000000(0000) GS:ffff888126173000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb1f4d5d000 CR3: 000000006072a000 CR4: 00000000003526f0
Call Trace:
<TASK>
__refcount_add include/linux/refcount.h:-1 [inline]
__refcount_inc include/linux/refcount.h:366 [inline]
refcount_inc include/linux/refcount.h:383 [inline]
fib_info_hold include/net/ip_fib.h:629 [inline]
nsim_fib4_prepare_event drivers/net/netdevsim/fib.c:930 [inline]
nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:1000 [inline]
nsim_fib_event_nb+0x1055/0x1240 drivers/net/netdevsim/fib.c:1043
call_fib_notifier+0x45/0x80 net/core/fib_notifier.c:25
call_fib_entry_notifier net/ipv4/fib_trie.c:90 [inline]
fib_leaf_notify net/ipv4/fib_trie.c:2176 [inline]
fib_table_notify net/ipv4/fib_trie.c:2194 [inline]
fib_notify+0x36b/0x5e0 net/ipv4/fib_trie.c:2217
fib_net_dump net/core/fib_notifier.c:70 [inline]
register_fib_notifier+0x184/0x360 net/core/fib_notifier.c:108
nsim_fib_create+0x85d/0x9f0 drivers/net/netdevsim/fib.c:1596
nsim_dev_reload_create drivers/net/netdevsim/dev.c:1604 [inline]
nsim_dev_reload_up+0x374/0x7c0 drivers/net/netdevsim/dev.c:1058
devlink_reload+0x501/0x8d0 net/devlink/dev.c:475
devlink_pernet_pre_exit+0x1ff/0x420 net/devlink/core.c:558
ops_pre_exit_list net/core/net_namespace.c:161 [inline]
ops_undo_list+0x187/0x940 net/core/net_namespace.c:234
cleanup_net+0x56e/0x800 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK> |
| In PHP versions 7.3.x below 7.3.13 and 7.4.0 on Windows, when supplying custom headers to mail() function, due to mistake introduced in commit 78f4b4a2dcf92ddbccea1bb95f8390a18ac3342e, if the header is supplied in lowercase, this can result in double-freeing certain memory locations. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: vgic: Fix race between LPI release and re-registration
Fix a potential race between decrementing an LPI's reference count and
evicting that structure from the LPI xarray.
LPI structures are maintained in the VGIC LPI xarray (dist->lpi_xa).
When the reference count of an LPI structure drops to zero,
vgic_release_lpi_locked() removes the structure from the xarray and
frees it under the xarray lock.
However, the release of an LPI can race with a concurrent LPI
re-registration with the same INTID via vgic_add_lpi() on another CPU,
since the reference count drop and the xarray eviction are not performed
in a single atomic step. This can happen e.g. if the guest issues a
DISCARD while the LPI is still referenced from a vCPU's active-pending
list (ap_list), and the same INTID is re-mapped via MAPTI.
Particularly, vgic_release_lpi_locked() is called from two distinct
paths: direct release via vgic_put_irq(), and deferred release via
vgic_release_deleted_lpis(). During direct release, the issue can result
in deleting a newly registered LPI from the xarray:
CPU0 (Releasing LPI) CPU1 (Adding new LPI)
==================== =====================
vgic_put_irq()
__vgic_put_irq()
refcount_dec_and_test()
vgic_add_lpi()
xa_lock_irqsave()
old_irq = xa_load(.., intid)
vgic_try_get_irq_ref(old_irq) == false
new IRQ inserted --> __xa_store(.., intid, ..)
xa_unlock_irqrestore()
xa_lock_irqsave();
vgic_release_lpi_locked()
__xa_erase(.., irq->intid) <-- BUG: new IRQ is erased
kfree_rcu(old_irq)
During the deferred release path, the old IRQ can be leaked:
CPU0 (Releasing LPI) CPU1 (Adding new LPI)
==================== =====================
vgic_put_irq_norelease()
__vgic_put_irq()
refcount_dec_and_test()
irq->pending_release = true
vgic_add_lpi()
xa_lock_irqsave()
old_irq = xa_load(.., intid)
vgic_try_get_irq_ref(oldirq) == false
BUG: old IRQ overwritten --> __xa_store(.., intid, ..)
xa_unlock_irqrestore()
vgic_release_deleted_lpis()
xa_lock_irqsave()
xa_for_each() { .. } <-- old IRQ with pending_release = true
is gone, so it cannot be released
To fix the direct release path, move the reference count drop inside
the xarray lock, making sure that vgic_add_lpi() never encounters the
to-be-released LPI.
In the deferred release path, the refcount drop must happen under a raw
spinlock, so the xarray lock cannot be grabbed, and the same solution
does not work. Instead, update vgic_add_lpi(), so that if it evicts
an LPI from the xarray, it takes on the responsibility of freeing it.
Consequently, an LPI may now be freed concurrently after a deferred
release drops the refcount, so accessing the pending_release field is no
longer safe from use-after-free. Delete all uses of the flag, and update
vgic_release_deleted_lpis() to identify orphaned LPIs purely based on
their refcount. |
| In the Linux kernel, the following vulnerability has been resolved:
iommufd: Destroy the pages content after detaching from dmabuf
Sashiko points out this has gotten out of order, the mutex could still be
in use through the dmabuf invalidation callbacks. Don't destroy any of the
pages content until the dmabuf is fully detached. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: seq: midi: Serialize output teardown with event_input
event_process_midi() borrows msynth->output_rfile.output and then
passes the substream to dump_midi() and snd_rawmidi_kernel_write()
without synchronizing with the output open/close transition.
midisynth_use() also publishes output_rfile before
snd_rawmidi_output_params() has finished.
The last midisynth_unuse() can therefore release the same rawmidi file
and free substream->runtime before snd_rawmidi_kernel_write1() takes
its runtime buffer reference. That leaves the event_input path using a
stale substream or runtime and can end in a NULL-deref or use-after-free.
Fix this with two pieces of synchronization. Keep a short IRQ-safe
spinlock only for publishing or clearing output_rfile and for pairing
the output snapshot with an snd_use_lock_t reference. Once
event_process_midi() has taken that in-flight reference, it drops the
spinlock before calling snd_seq_dump_var_event(), dump_midi(), or
snd_rawmidi_kernel_write(). midisynth_unuse() now detaches the visible
rawmidi file under the same spinlock, waits for the in-flight writers
to drain, and only then drains and releases the saved file.
midisynth_use() likewise opens into a local snd_rawmidi_file and
publishes it only after snd_rawmidi_output_params() succeeds.
The buggy scenario involves two paths, with each column showing the
order within that path:
event_input path: last unuse path:
1. event_process_midi() snapshots 1. midisynth_unuse() starts
output_rfile.output. tearing down output_rfile.
2. dump_midi() reaches 2. snd_rawmidi_kernel_release()
snd_rawmidi_kernel_write() closes the output file.
before runtime is pinned. 3. close_substream() frees
3. The callback keeps using substream->runtime.
the borrowed substream.
Validation reproduced this kernel report:
KASAN null-ptr-deref in snd_rawmidi_kernel_write1+0x56/0x360
RIP: 0033:0x7fde7dd0837f
RIP: 0010:snd_rawmidi_kernel_write1+0x56/0x360 |
| In the Linux kernel, the following vulnerability has been resolved:
dlm: fix add msg handle in send_queue ordered
In a benchmark scenario triggering a lot of requests that triggers a lot
of DLM messages on the network it can be that the mh->seq is not ordered
according the oldest seq number. This ordering is required by
dlm_receive_ack as "before(mh->seq, seq)" will stop to check for older
sequence numbers that are ordered in the tail of "node->send_queue".
The side effects of not having it correct ordered regarding
"before(mh->seq, seq)" are refcounting issues and use-after free.
I only was able to reproduce this issue in a experimental DLM branch
and a user space DLM benchmark that uses io_uring. After changing this I
don't experienced any refcounting with the sending buffer issues anymore. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: Fix advertising data UAFs
hci_find_adv_instance() returns an adv_info pointer that is valid only
while hdev->lock is held. The advertising command-sync paths perform
instance lookups without that lock and, in some cases, retain the pointer
while waiting for a controller response.
An advertising termination event can therefore interleave as follows:
hci_cmd_sync_work hci_rx_work
hci_find_adv_instance()
__hci_cmd_sync_status()
wait for controller reply hci_dev_lock()
hci_remove_adv_instance()
kfree(adv)
adv->scan_rsp_changed = false
KASAN reported:
BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300
Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
hci_set_ext_scan_rsp_data_sync+0x2e1/0x300
hci_schedule_adv_instance_sync+0x390/0x4c0
hci_cmd_sync_work+0x173/0x300
Allocated by task 87:
hci_add_adv_instance+0x538/0xac0
add_advertising+0x885/0x1160
Freed by task 89:
kfree+0x131/0x3c0
hci_remove_adv_instance+0x1d8/0x3b0
hci_le_ext_adv_term_evt+0x17b/0x730
Protect the instance lookup and payload construction in the extended
advertising, scan response, and periodic advertising data paths. Snapshot
the advertising parameters under hdev->lock, but release the lock before
waiting for the controller.
Clear advertising-data dirty bits before issuing their commands and
restore them after a failure using a fresh lookup. Likewise, update the
reported transmit power through a fresh lookup after the parameter command
completes. No adv_info pointer then survives an HCI command wait. |
| In the Linux kernel, the following vulnerability has been resolved:
dibs: fix use-after-free of dmb_node in loopback attach/detach/unregister
dibs_lo_attach_dmb(), dibs_lo_detach_dmb() and dibs_lo_unregister_dmb()
look up the dmb_node under dmb_ht_lock, drop the lock and only then
operate on the node's refcount. Nothing keeps the node alive across
that window: __dibs_lo_unregister_dmb() removes the node from the hash
table under the write lock and immediately frees it.
A concurrent final put can therefore free the node between the lookup
and the refcount operation:
CPU0 (attach) CPU1 (owner unregisters)
read_lock_bh(&dmb_ht_lock)
find dmb_node (refcnt == 1)
read_unlock_bh(&dmb_ht_lock)
refcount_dec_and_test() 1 -> 0
write_lock_bh(&dmb_ht_lock)
hash_del(&dmb_node->list)
write_unlock_bh(&dmb_ht_lock)
kfree(dmb_node)
refcount_inc_not_zero(&dmb_node->refcnt) <-- use-after-free
The same window exists for the refcount_dec_and_test() calls in the
detach and unregister paths.
Close the race structurally by making hash table membership and the
refcount transitions atomic with respect to each other:
- Perform the final refcount_dec_and_test() and hash_del() in a single
dmb_ht_lock write-side critical section, in both the unregister and
the detach path. Freeing the node still happens after the lock is
dropped, which is safe because a node whose refcount reached zero has
left the hash table and can no longer be found.
- This establishes the invariant that any node found in the hash table
holds at least one reference, and that the final reference can only
be dropped under the write lock. dibs_lo_attach_dmb() can thus take
its reference with a plain refcount_inc() while still holding the
read lock; refcount_inc_not_zero() is no longer needed.
__dibs_lo_unregister_dmb() no longer touches the hash table and is
renamed to dibs_lo_free_dmb() accordingly.
Note: commit cc21191b584c ("dibs: Move data path to dibs layer") moved
the code to its current location; the race was introduced earlier by
commit c3a910f2380f ("net/smc: implement DMB-merged operations of
loopback-ism").
Tested SMC-D via ISM and dibs loopback. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp
l2cap_le_connect_rsp() obtains a channel via
__l2cap_get_chan_by_ident() but neither holds a reference nor uses
l2cap_chan_hold_unless_zero() before locking and operating on it.
A concurrent l2cap_chan_del() triggered by a remote disconnect can
free the channel between the lookup and l2cap_chan_lock(), causing
a use-after-free.
The BR/EDR counterpart l2cap_connect_rsp() and the sibling handler
l2cap_le_command_rej() already use l2cap_chan_hold_unless_zero()
to safely hold a reference, but l2cap_le_connect_rsp() was left
unprotected.
Fix by adding l2cap_chan_hold_unless_zero() after the ident lookup
and l2cap_chan_put() on the exit path, consistent with other L2CAP
response handlers. |
| In the Linux kernel, the following vulnerability has been resolved:
forcedeth: fix UAF of txrx_stats in nv_remove
nv_remove() frees the per-CPU txrx_stats before unregister_netdev().
Until unregister completes, ndo_get_stats64, the NAPI/xmit data path,
and nv_close()/drain may still access txrx_stats, leading to a
use-after-free.
Free the stats only after unregister_netdev(). |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: make nft_object rhltable per table
The nft_object rhltable is global, this allows for accessing objects
that are being dismangled from lookup path by other existing netns.
Given the nft_obj_destroy() releases the object inmediately, this might
lead to use-after-free of these objects that are being released.
Make the existing rhltable per table to address this issue to deal with
with the nft_rcv_nl_event() path too.
Update nft_obj_lookup() to take the table as non-const, otherwise,
compiler complains when passing the objname_ht to rhltable_lookup(). |
| In the Linux kernel, the following vulnerability has been resolved:
staging: nvec: fix use-after-free in nvec_rx_completed()
In nvec_rx_completed(), when an incomplete RX transfer is detected,
nvec_msg_free() is called to return the message back to the pool by
clearing its 'used' atomic flag. Immediately after this, the code
accesses nvec->rx->data[0] to check the message type.
Since nvec_msg_free() marks the pool slot as available via atomic_set(),
any concurrent or subsequent call to nvec_msg_alloc() could claim that
same slot and overwrite its data[] array. Reading nvec->rx->data[0] after
freeing the message is therefore a use-after-free.
Fix this by saving the message type byte before calling nvec_msg_free(),
then using the saved value for the battery quirk check. |
| In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix UAF in rxgk_issue_challenge()
Fix rxgk_issue_challenge() to free the page containing the challenge
content after invoking the tracepoint as the whdr passed to the tracepoint
points into the page just freed. |
| In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Don't move a peeked OOB message onto the pending queue
rxrpc_recvmsg_oob() takes a received oob message off recvmsg_oobq and,
if a response is needed, moves it onto the pending_oobq tree. However,
only the unlink from recvmsg_oobq is guarded by MSG_PEEK; the move onto
pending_oobq always runs.
As a result, reading a challenge with MSG_PEEK leaves the skb on
recvmsg_oobq while also adding it to pending_oobq. Since struct
sk_buff's rbnode shares storage with its next and prev pointers,
rb_insert_color() overwrites the list linkage, and the skb, which holds
a single reference, becomes reachable from both queues at once.
When the socket is closed both queues are drained in turn. While
draining recvmsg_oobq, __skb_unlink() follows the next and prev
pointers that rbnode has overwritten and writes to a bad address. Also,
as the skb holds a single reference but is freed from each queue, both
the skb and the connection reference it holds are released twice. This
leads to memory corruption and to a use-after-free caused by the
connection refcount underflow.
MSG_PEEK does not consume the message from the queue, so only unlink it
from recvmsg_oobq and then move it onto pending_oobq or free it when
the message is actually consumed. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/huge_memory: unlock i_mmap_rwsem before releasing after-split folios
__folio_split() keeps dereferencing the mapping after the split:
shmem_uncharge(mapping->host) and remap_page() while the folios are still
frozen/locked, and i_mmap_unlock_read(mapping) at the very end, after the
after-split folios have been unlocked and freed.
Nothing holds an inode reference across that. The split relies on @folio
-- which the beyond-EOF drop loop never removes, as it starts at
folio_next(folio) -- staying locked and in the page cache to hold off
eviction. But the unlock loop unlocks @folio before i_mmap_unlock_read()
runs. If the caller's @lock_at is a tail beyond EOF, as memory_failure()
passes when splitting a poisoned tail of a shmem THP that reaches past
i_size during truncation, it too is gone from the page cache; so once
@folio is unlocked no locked, in-cache folio pins the inode, and a
concurrent final iput() can evict and RCU-free it before
i_mmap_unlock_read() touches i_mmap_rwsem:
BUG: KASAN: slab-use-after-free in __up_read+0x634/0x790
i_mmap_unlock_read include/linux/fs.h:537 [inline]
__folio_split+0x732/0x1640 mm/huge_memory.c:4100
try_to_split_thp_page+0xab/0x390 mm/memory-failure.c:1675
memory_failure+0x1394/0x26e0 mm/memory-failure.c:2470
Freed by task 4601:
shmem_free_in_core_inode+0x54/0xb0 mm/shmem.c:5177
evict+0x57f/0xac0 fs/inode.c:870
Do every mapping dereference while @folio still pins the inode: drop
i_mmap_rwsem right after remap_page(), before the loop that unlocks and
frees the after-split folios, and clear @mapping so the exit path does not
unlock it again. shmem_uncharge() and remap_page() already run before
that point, so after this nothing past the unlock loop touches the inode
or the mapping.
This is now a rule the split depends on, alongside keeping @folio frozen
until the page cache is updated: no inode or mapping dereference once the
after-split folios start being unlocked. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: fix tid_tx use-after-free on BA session stop
ieee80211_stop_tx_ba_cb() hands tid_tx to kfree_rcu() through
ieee80211_remove_tid_tx(), and then reads tid_tx->ndp after dropping
sta->lock:
ieee80211_remove_tid_tx(sta, tid); /* kfree_rcu(tid_tx, rcu_head) */
...
spin_unlock_bh(&sta->lock);
if (start_txq)
ieee80211_agg_start_txq(sta, tid, false);
if (send_delba)
ieee80211_send_delba(..., tid_tx->ndp);
That read is not covered by an RCU read-side critical section, and it runs
in preemptible process context: both callers hold the wiphy mutex, reaching
it either from the ieee80211_ba_session_work() wiphy work or from
ieee80211_sta_tear_down_BA_sessions() during station teardown.
Softirqs can run in that window too, both from the local_bh_enable() that
ends ieee80211_agg_start_txq() and from any interrupt exit, so the RCU
callback can free tid_tx before the read.
Driving the function from a test module with the grace period forced into
that window, KASAN reports the read, and the free arrives on the ordinary
RCU softirq path:
BUG: KASAN: slab-use-after-free in ieee80211_stop_tx_ba_cb+0x3cd/0x400
Read of size 1 at addr ffff888002b9f52e by task kworker/0:1/10
[...]
Freed by task 57:
__kasan_slab_free+0x47/0x70
__rcu_free_sheaf_prepare+0x70/0x250
rcu_free_sheaf_nobarn+0x18/0x40
rcu_core+0x426/0x1310
handle_softirqs+0x144/0x590
__irq_exit_rcu+0xea/0x150
irq_exit_rcu+0x9/0x20
sysvec_apic_timer_interrupt+0x6b/0x80
asm_sysvec_apic_timer_interrupt+0x1a/0x20
send_delba is only set when tx_stop is set, which happens for
AGG_STOP_LOCAL_REQUEST alone, so this is reached on local teardown -
session idle timeout, PTK rekey, suspend, HW reconfig - and not from a
peer's DELBA.
Read ndp into a local before the session is freed, while sta->lock is still
held. tid_tx->ndp has a single writer, in
ieee80211_tx_ba_session_handle_start(), which cannot run concurrently here:
both paths are serialised by the wiphy mutex, and the session is already
marked HT_AGG_STATE_STOPPING at this point. tid_tx->ndp is also the only
tid_tx dereference left after ieee80211_remove_tid_tx() in this function.
[move/change the comment a bit to be more general not just on ndp,
initialize ndp directly] |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: idxd: fix fdev setup failure cleanup in idxd_cdev_open()
The failed_dev_add and failed_dev_name paths drop the file-device
reference while wq->wq_lock is still held. If put_device(fdev) drops the
last reference, idxd_file_dev_release() runs synchronously and tries to
take wq->wq_lock again, deadlocking.
Those paths also fall through into the later ctx cleanup labels even
though idxd_file_dev_release() owns that cleanup and frees ctx. This can
make idxd_xa_pasid_remove(ctx) and kfree(ctx) operate on a freed context.
Move idxd_wq_get() before file-device setup can fail, since the release
callback always calls idxd_wq_put(). Then unlock wq->wq_lock before
put_device(fdev) and return directly from the file-device setup failure
path, leaving ctx cleanup to the release callback. |
